The human memory is crucial to a trial. It is the essence of a lay person’s testimony. So where does memory come from?

In the Organized Mind neuroscientist Daniel Levitin explains.

When we experience an event, a unique set of neurons is activated. The act of remembering something is a process of bringing back on line those neurons that were involved in the original experience… Once we get those neurons to become active in a fashion similar to how they were during the original event, we experience the memory as a lower-resolution replay of the original event. If only we could get every one of those original neurons active in exactly the same way they were the first time, our recollection would be strikingly vivid and realistic. Remembering is imperfect; the instructions for which neurons need to be gathered and how exactly they need to fire are weak and degraded, leading to a representation that is only a dim and often inaccurate copy of the real experience. Memory is fiction. It may present itself to us as a fact, but it is highly susceptible to distortion. Memory is not just a replaying, but a rewriting.

We have a better time remembering unique events. For example, the memory of locking your front door today may be forgotten. You lock the front door every day, so the experience shares similarities with many other door locking times. Making it easier for the brain to get fooled by competing memories.

However, out of the ordinary events are easier to retrieve. “[T]here is nothing competing with them when your brain tries to access them from its storehouse of remembered events.” Memory retrieval requires our brains to sort through multiple instances and pick out the one we are trying to collect.

Evolutionary wise it makes sense that we have an easier time remembering unique events. We need to register the change in order to maximize our chance for survival.

Additionally, having a strong emotion attached to an event, makes it easier to remember. A strong emotion can consist of being frightened, elated, sad, or angry. These emotions make it more likely that we will remember the event. This is because our brain creates neurochemical tags that accompany the experience. It is like placing a highlighter over the event.

Again this highlighting function makes sense from an evolutionary standpoint. If a strong emotion is linked to the event, it’s probably because we need to remember it for our survival. E.g. the smell of rotten food or being backstabbed by a friend. Unfortunately, even though we may have an easier time retrieving the memory, the “highlighter” associated with emotion doesn’t mean the memory is more accurate.

Memory is fallible.

(Views are my own and do not represent the views of any organization.)